The Imaging Research Core Facility provides researchers with the state-of-the art facilities and services for in vivo imaging. The facility provides cancer researchers its extensive imaging research infrastructure and expertise of -15 imaging faculty in Radiology and Biomedical Engineering to enhance and expand their ongoing research efforts. The advent of dedicated small animal imaging systems allows the integration of in vivo physiologic measurements with microscopic measurements of structural and cellular activities. The collaborative, multi-disciplinary approach provides a wealth of new information in elucidating the complex relationship between structure, genetics, replication, and function in genetically manipulated animal models of disease that have been used widely in cancer research with grounding in cellular/molecular-level understanding. The Imaging Research Core Facility is the centerpiece of the Case Center for Imaging Research which encompasses all aspects of the much broader imaging research program at Case/UHC. This includes molecular imaging, small animal imaging, and clinical imaging thrusts. Many of these thrusts are directly tied to the Case Comprehensive Cancer Center (Case CCC). The Imaging Research Core Facility's molecular and small animal imaging services, technologies, and research programs are described in detail below. Clinical imaging research programs are described in more detail in the Program 7: Developmental Therapeutics proposal.